Polymeric materials

ABSTRACT

A polymeric material has a repeat unit of formula —O-Ph-O-Ph-CO-Ph- I and a repeat unit of formula —O-Ph-Ph-O-Ph-CO-Ph- II wherein Ph represents a phenylene moiety; wherein the repeat units I and II are in the relative molar properties I:II of from 65:35 to 95:5; wherein log 10  (X %)&gt;1.50-0.26 MV; wherein X % refers to the % crystallinity measured as described in Example 31 and MV refers to the melt viscosity measured as described in Example 30. A process for making the polymeric material comprises polycondensing a mixture of at least one dihydroxybenzene compound and at least one dihydroxybiphenyl compound in the molar proportions 65:35 to 95:5 with at least one dihalobenzophenone in the presence of sodium carbonate and potassium carbonate wherein: (i) the mole % of said potassium carbonate is at least 2.5 and/or (ii) the following relationship applies 
     
       
         
           
             
               
                 
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BACKGROUND OF THE INVENTION

This invention relates to polymeric materials. Preferred embodimentsrelate to thermoplastic composites comprising polymeric materials foruse, for example, in the composites industry.

There is a wide range of thermoplastic polymeric material available foruse in industry, either alone or as part of composite materials.However, industry is constantly demanding materials with propertieswhich are improved in at least some respect over existing materials.

Polyphenylene sulphide (PPS) is a known polymeric material with arelatively low melting temperature (Tm) of 290° C.; however its glasstransition temperature (Tg) is 85° C. to 100° C. which is too low forsome applications. On the other hand, polyetheretherketone (PEEK) has asuitable Tg of 143° C. but its Tm of 343° C. is much higher thandesirable. Nonetheless, PEEK is the material of choice for manycommercial applications because it is highly crystalline and hasoutstanding chemical resistance properties.

U.S. Pat. No. 4,717,761 (ICI) describes a polymer containing-ether-phenyl-ether-phenyl-carbonyl-phenyl- (i.e. PEEK) and-ether-phenyl-phenyl-ether-phenyl-carbonyl-phenyl- (i.e. PEDEK) repeatunits. The copolymer is said to have a low Tm. However, there is nodisclosure in the cited reference relating to the level of crystallinityof the copolymer and/or how chemically (e.g. solvent) resistant it maybe in use.

It is an object of the present invention to provide a polymeric materialper se and a method of making such a polymeric material having arelatively low Tm, a relatively high Tg and a relatively highcrystallinity.

SUMMARY OF THE INVENTION

This invention is based on the discovery of a method for makingcopolymers of PEEK and PEDEK of increased crystallinity compared tomaterials described in U.S. Pat. No. 4,717,761 and novel PEEK/PEDEKcopolymers per se.

According to a first aspect of the invention, there is provided apolymeric material having a repeat unit of formula—O-Ph-O-Ph-CO-Ph-  Iand a repeat unit of formula—O-Ph-Ph-O-Ph-CO-Ph-  IIwherein Ph represents a phenylene moietywherein the repeat units I and Hare in the relative molar proportionsI:II of from 65:35 to 95:5; andwherein log₁₀ (X %)>1.50-0.26 MV;wherein X % refers to the % crystallinity measured as described inExample 31 and MV refers to the melt viscosity measured as described inExample 30.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a graph of log₁₀ (X %), wherein X refers to the crystallinityv. melt viscosity (MV) for various PEEK:PEDEK polymeric materials madeusing various processes.

FIG. 2 is a schematic describing the relationship between D50 of sodiumcarbonate and mole % excess of potassium carbonate

DETAILED DESCRIPTION OF THE INVENTION

The phenylene moieties (Ph) in each repeat unit may independently have1,4-para linkages to atoms to which they are bonded or 1,3-metalinkages. Where a phenylene moiety includes 1,3-linkages, the moietywill be in the amorphous phase of the polymer. Crystalline phases willinclude phenylene moieties with 1,4-linkages. In many applications it ispreferred for the polymeric material to be highly crystalline and,accordingly, the polymeric material preferably includes high levels ofphenylene moieties with 1,4-linkages.

In a preferred embodiment, at least 95%, preferably at least 99%, of thenumber of phenylene moieties (Ph) in the repeat unit of formula I have1,4-linkages to moieties to which they are bonded. It is especiallypreferred that each phenylene moiety in the repeat unit of formula I has1,4-linkages to moieties to which it is bonded.

In a preferred embodiment, at least 95%, preferably at least 99%, of thenumber of phenylene moieties (Ph) in the repeat unit of formula II have1,4-linkages to moieties to which they are bonded. It is especiallypreferred that each phenylene moiety in the repeat unit of formula IIhas 1,4-linkages to moieties to which it is bonded.

Preferably, the phenylene moieties in repeat unit of formula I areunsubstituted. Preferably, the phenylene moieties in repeat unit offormula II are unsubstituted.

Said repeat unit of formula I suitably has the structure

Said repeat unit of formula II suitably has the structure

Preferred polymeric materials in accordance with the invention have acrystallinity which is greater than expected from the prior art.Preferably, log₁₀ (X %)>1.50-0.23 MV. More preferably log₁₀ (X%)>1.50-0.28 MV+0.06 MV². The derivation of the aforementionedrelationships is discussed hereinafter with reference to FIG. 1.

Said polymeric material may include at least 68 mol %, preferably atleast 71 mol % of repeat units of formula I. Particular advantageouspolymeric materials may include at least 72 mol %, or, especially, atleast 74 mol % of repeat units of formula I. Said polymeric material mayinclude less than 90 mol %, suitably 82 mol % or less of repeat units offormula I. Said polymeric material may include 68 to 82 mol %,preferably 70 to 80 mol %, more preferably 72 to 77 mol % of units offormula I.

Said polymeric material may include at least 10 mol %, preferably atleast 18 mol %, of repeat units of formula II. Said polymeric materialmay include less than 32 mol %, preferably less than 29 mol % of repeatunits of formula II. Particularly advantageous polymeric materials mayinclude 28 mol % or less; or 26 mol % or less of repeat units of formulaII. Said polymeric material may include 18 to 32 mol %, preferably 20 to30 mol %, more preferably 23 to 28 mol % of units of formula II.

The sum of the mol % of units of formula I and II in said polymericmaterial is suitably at least 95 mol %, is preferably at least 98 mol %,is more preferably at least 99 mol % and, especially, is about 100 mol%.

The ratio defined as the mol % of units of formula I divided by the mol% of units of formula II may be in the range 1.8 to 5.6, is suitably inthe range 2.3 to 4 and is preferably in the range 2.6 to 3.3.

The Tm of said polymeric material (suitably measured as describedherein) may be less than 330° C., is suitably less than 320° C., ispreferably less than 310° C. In some embodiments, the Tm may be lessthan 306° C. The Tm may be greater than 280° C., or greater than 290°C., 295° C. or 300° C. The Tm is preferably in the range 300° C. to 310°C.

The Tg of said polymeric material (suitably measured as describedherein) may be greater than 130° C., preferably greater than 135° C.,more preferably 140° C. or greater. The Tg may be less than 175° C.,less than 165° C., less than 160° C. or less than 155° C. The Tg ispreferably in the range 145° C. to 155° C.

The difference (Tm−Tg) between the Tm and Tg may be at least 130° C.,preferably at least 140° C., more preferably at least 150° C. Thedifference may be less than 170° C. or less than 165° C. In a preferredembodiment, the difference is in the range 145-165° C.

In a preferred embodiment, said polymeric material has a Tg in the range145° C.-155° C., a Tm in the range 300° C. to 310° C. and the differencebetween the Tm and Tg is in the range 145° C. to 165° C.

Said polymeric material may have a crystallinity measured as describedin Example 31 of at least 25%.

Said polymeric material suitably has a melt viscosity (MV) of at least0.10 kNsm⁻², preferably has a MV of at least 0.15 kNsm⁻², morepreferably at least 0.20 kNsm⁻², especially at least 0.25 kNsm⁻². MV issuitably measured using capillary rheometry operating at 340° C. at ashear rate of 1000 s⁻¹ using a tungsten carbide die, 0.5 mm×3.175 mm.Said polymeric material may have a MV of less than 1.8 kNsm⁻², suitablyless than 1.2 kNsm⁻².

Said polymeric material may have a tensile strength, measured inaccordance with ISO527 of at least 40 MPa, preferably at least 60 MPa,more preferably at least 80 MPa. The tensile strength is preferably inthe range 80-110 MPa, more preferably in the range 80-100 MPa.

Said polymeric material may have a flexural strength, measured inaccordance with ISO178 of at least 130 MPa. The flexural strength ispreferably in the range 135-180 MPa, more preferably in the range140-150 MPa.

Said polymeric material may have a flexural modulus, measured inaccordance with ISO178 of at least 2 GPa, preferably at least 3 GPa. Theflexural modulus is preferably in the range 3.0-4.5 GPa, more preferablyin the range 3.0-4.0 GPa.

Said polymeric material may be in the form of pellets or granules,wherein the pellets or granules include at least 95 wt %, preferably atleast 99 wt %, especially about 100 wt % of said polymeric material.Pellets or granules may have a maximum dimension of less than 10 mm,preferably less than 7.5 mm, more preferably less than 5.0 mm.

Said polymeric material may be part of a composition which may includesaid polymeric material and a filler means. Said filler means mayinclude a fibrous filler or a non-fibrous filler. Said filler means mayinclude both a fibrous filler and a non-fibrous filler. A said fibrousfiller may be continuous or discontinuous.

A said fibrous filler may be selected from inorganic fibrous materials,non-melting and high-melting organic fibrous materials, such as aramidfibres, and carbon fibre.

A said fibrous filler may be selected from glass fibre, carbon fibre,asbestos fibre, silica fibre, alumina fibre, zirconia fibre, boronnitride fibre, silicon nitride fibre, boron fibre, fluorocarbon resinfibre and potassium titanate fibre. Preferred fibrous fillers are glassfibre and carbon fibre.

A fibrous filler may comprise nanofibres.

A said non-fibrous filler may be selected from mica, silica, talc,alumina, kaolin, calcium sulfate, calcium carbonate, titanium oxide,ferrite, clay, glass powder, zinc oxide, nickel carbonate, iron oxide,quartz powder, magnesium carbonate, fluorocarbon resin, graphite, carbonpowder, nanotubes and barium sulfate. The non-fibrous fillers may beintroduced in the form of powder or flaky particles.

Said composition may define a composite material which could be preparedas described in Impregnation Techniques for Thermoplastic MatrixComposites. A Miller and A G Gibson, Polymer & Polymer Composites 4(7),459-481 (1996), EP102158 and EP102159, the contents of which areincorporated herein by reference. Preferably, in the method, saidpolymeric material and said filler means are mixed at an elevatedtemperature, suitably at a temperature at or above the meltingtemperature of said polymeric material. Thus, suitably, said polymericmaterial and filler means are mixed whilst the polymeric material ismolten. Said elevated temperature is suitably below the decompositiontemperature of the polymeric material. Said elevated temperature ispreferably at or above the main peak of the melting endotherm (Tm) forsaid polymeric material. Said elevated temperature is preferably atleast 300° C. Advantageously, the molten polymeric material can readilywet the filler and/or penetrate consolidated fillers, such as fibrousmats or woven fabrics, so the composite material prepared comprises thepolymeric material and filler means which is substantially uniformlydispersed throughout the polymeric material.

The composite material may be prepared in a substantially continuousprocess. In this case polymeric material and filler means may beconstantly fed to a location wherein they are mixed and heated. Anexample of such a continuous process is extrusion. Another example(which may be particularly relevant wherein the filler means comprises afibrous filler) involves causing a continuous filamentous mass to movethrough a melt or aqueous dispersion comprising said polymeric material.The continuous filamentous mass may comprise a continuous length offibrous filler or, more preferably, a plurality of continuous filamentswhich have been consolidated at least to some extent. The continuousfibrous mass may comprise a tow, roving, braid, woven fabric or unwovenfabric. The filaments which make up the fibrous mass may be arrangedsubstantially uniformly or randomly within the mass. A compositematerial could be prepared as described in PCT/GB2003/001872, U.S. Pat.No. 6,372,294 or EP1215022.

Alternatively, the composite material may be prepared in a discontinuousprocess. In this case, a predetermined amount of said polymeric materialand a predetermined amount of said filler means may be selected andcontacted and a composite material prepared by causing the polymericmaterial to melt and causing the polymeric material and filler means tomix to form a substantially uniform composite material.

The composite material may be formed into a particulate form for exampleinto pellets or granules. Pellets or granules may have a maximumdimension of less than 10 mm, preferably less than 7.5 mm, morepreferably less than 5.0 mm.

Preferably, said filler means comprises one or more fillers selectedfrom glass fibre, carbon fibre, carbon black and a fluorocarbon resin.More preferably, said filler means comprises glass fibre or carbonfibre.

A composition or composite material as described may include 20 to 99.9wt % (e.g. 20 to 70 wt %) of said polymeric material and 0.1 to 80 wt %(e.g. 30 to 80 wt %) of filler means. Preferred embodiments includegreater than 10 wt %, more preferably greater than 40 wt % of fillermeans.

The invention extends to a composite material as described per se.

According to a second aspect of the invention, there is provided aprocess for the production of a polymeric material having a repeat unitof formula—O-Ph-O-Ph-CO-Ph-  Iand a repeat unit of formula—O-Ph-Ph-O-Ph-CO-Ph-  IIwherein Ph represents a phenylene moiety, said process comprisingpolycondensing a mixture of at least one dihydroxybenzene compound andat least one dihydroxybiphenyl compound in the molar proportions 65:35to 95:5 with at least one dihalobenzophenone in the presence of sodiumcarbonate and potassium carbonate wherein:(i) the mole % of said potassium carbonate is at least 2.5 and/or(ii) the following relationship (referred to as the “D50/mole %relationship”) applies

$\frac{{the}\mspace{14mu} D_{50}\mspace{14mu}{of}\mspace{14mu}{said}\mspace{14mu}{sodium}\mspace{14mu}{carbonate}\mspace{14mu}{in}\mspace{14mu}{µm}}{{mole}\mspace{14mu}\%\mspace{14mu}{of}\mspace{14mu}{potassium}\mspace{14mu}{carbonate}} = {< 46}$

The D50 of the sodium carbonate may be measured as described in Example29.

The mole % of said potassium carbonate is suitably defined as:

$\frac{{the}\mspace{14mu}{number}\mspace{14mu}{of}\mspace{14mu}{moles}\mspace{14mu}{of}\mspace{14mu}{potassium}\mspace{14mu}{carbonate}}{{the}\mspace{14mu}{total}\mspace{14mu}{number}\mspace{14mu}{of}\mspace{14mu}{moles}\mspace{14mu}{of}\mspace{14mu}{hydroxy}\mspace{14mu}{{monomer}(s)}\mspace{14mu}{used}} \times 100\%$

Under option (i), the mole % of said potassium carbonate may be at least3 mole %, is preferably at least 3.5 mole %, is more preferably at least3.9 mole %. The mole % of said potassium carbonate may be less than 10mole %, preferably less than 8 mole %, more preferably less than 6 mole%, especially less than 5 mole %. Preferably, the mole % of saidpotassium carbonate is in the range 3.5 to 6 mole %, more preferably inthe range 3.5 to 4.9 mole %.

The total mole % of carbonates used in the method (i.e. the total numberof moles of carbonates used in method divided by the total number ofmoles of hydroxy monomer(s) used, expressed as a percentage) is suitablyat least 100%.

The total mole % of carbonates may be greater than 100 mole %. It may beless than 105 mole %.

The mole % of sodium carbonate used in the method may be at least 90mole %, preferably at least 92 mole %, more preferably at least 95 mole%.

The sum of the mole % (again related to the moles of hydroxy monomer(s))of sodium carbonate and potassium carbonate used in the method ispreferably at least 100 mole % and is more preferably greater than 100mole %. It may be in the range 100-105 mole %.

The mole % of carbonates (which term is intended to encompass carbonate(CO₃ ²⁻) and bicarbonate (HCO₃ ⁻)) other than sodium carbonate andpotassium carbonate used in the method is preferably less than 5 mole %,more preferably less than 1 mole % (again related to the moles ofhydroxy monomer(s)).

Preferably, the only carbonates used in the method are sodium carbonateand potassium carbonate.

Under option (ii), the D50/mole % relationship is preferably less than44, more preferably less than 42, especially less than 40. Saidrelationship may be less than 30 or 26. D50 is suitably measured asdescribed in Example 29.

Preferably, both the relationships described in options (i) and (ii)apply.

The potassium carbonate selected for use in the method is preferablyable to pass through a 500 μm mesh screen.

The D50 of said sodium carbonate is suitably less than 140 μm,preferably less than 125 μm, more preferably less than 110 μm. The D50may be at least 50 μm.

In the second aspect, the repeat units of formulas I and II may be asdescribed above in said first aspect. Thus, the phenylene moieties maybe as described in the first aspect. Preferably, therefore, said repeatunit of formula I suitably has the structure

Said repeat unit of formula II suitably has the structure

The process of the second aspect may comprise selecting adihydroxybenzene compound of formula

and selecting a dihydroxybiphenyl compound of formula

The molar proportions of compounds V and VI are preferably in the range65:35 to 95:5. The molar proportions may be in the range 68:32-90:10,preferably in the range 70:30-80:20, more preferably in the range72:28-77.23.

The process may comprise polycondensing said compounds of formulas V andVI with a compound of formula

where X¹ and X² independently represent halogen atoms preferablyselected from chlorine and fluorine atoms. Preferably, X¹ and X²represent fluorine atoms.

Preferably, the number of moles of monomers which include chlorine orfluorine atoms which are polycondensed in the process are at least equalto the number of moles of monomers which include two hydroxy groups(e.g. compounds V and VI). It is especially preferred that the number ofmoles of monomers which include chlorine or fluorine atoms (e.g.compound VII) is slightly greater than the number of moles of monomerswhich include two hydroxy groups.

Preferably, at least 95 wt %, more preferably at least 99 wt % ofmonomers used in the process are made up of monomers of formulae V, VIand VII. Preferably, substantially the only monomers used in the processare those of formulae V, VI and VII.

Said process of the second aspect is preferably carried out in thepresence of a solvent. The solvent may be of formula

where W is a direct link, an oxygen atom or two hydrogen atoms (oneattached to each benzene ring) and Z and Z′, which may be the same ordifferent, are hydrogen atoms or phenyl groups. Examples of sucharomatic sulphones include diphenylsulphone, dibenzothiophen dioxide,phenoxanthin dioxide and 4-phenylsulphonyl biphenyl. Diphenylsulphone isa preferred solvent.

The process is preferably carried out under substantially anhydrousconditions. In the process, the compounds of formula V, VI and VII aresuitably contacted in the presence of said solvent, especiallydiphenylsulphone. Polymerisation is suitably effected at a temperaturewithin the range 150°-400° C. In the process, the reactants are suitablyheated up to a maximum temperature which may be greater than 300° C.,for example in the range 300° C. to 350° C. Preferably, however, priorto reaching the maximum temperature, the reagents may be held at one ormore temperatures lower than the maximum temperature. For example, theprocess may involve holding the reagents at a temperature within therange 160-200° C. for at least 20 minutes; and/or may involve holdingthe reagents at a temperature within the range 200 to 240° C. for atleast 20 minutes.

The process of the second aspect is preferably for making a polymericmaterial of the first aspect.

Any invention described herein may be combined with any feature of anyother invention described herein mutatis mutandis.

Specific embodiments of the invention will now be described, by way ofexample, with reference to the figures wherein:

FIG. 1 is a graph of log₁₀ (X %), wherein X refers to the crystallinityv. melt viscosity (MV) for various PEEK:PEDEK polymeric materials madeusing various processes;

FIG. 2 is a schematic describing the relationship between D₅₀ of sodiumcarbonate and mole % excess of potassium carbonate.

The following are referred to herein:

PEEK 150—refers to polyetheretherketone supplied by VictrexManufacturing Limited which has a melt viscosity, measured usingcapillary rheometry operating at 400° C. and a shear rate of 1000 s⁻¹using a tungsten carbide die (0.5 mm×3.175 mm), of 0.15 kNsm⁻².

Polymers were prepared as described in Example 1 to 28. Subsequentexamples include details on procedures and tests undertaken.

Example 1—Preparation of 0.5 Mol Polyetheretherketone(PEEK)-Polyetherdiphenyletherketone (PEDEK) Copolymer

A 0.5 litre flanged flask fitted with a ground glass lid,stirrer/stirrer guide, nitrogen inlet and outlet was charged with4,4′-diflurobenzophenone (111.29 g, 0.510 mol), 1,4-dihydroxybenzene(41.30 g, 0.375 mol), 4,4′-dihydroxydiphenyl (23.28 g, 0.125 mol) anddiphenylsulphone (241.07 g) and purged with nitrogen for 1 hour. Thecontents were then heated under a nitrogen blanket to 160° C. to form analmost colourless solution. While maintaining a nitrogen blanket, driedsodium carbonate (53.00 g, 0.5 mol) and potassium carbonate (2.76 g,0.02 mol), both sieved through a screen with a mesh size of 500micrometres, were added. The temperature was raised to 185° C. at 1°C./min and held for 100 minutes. The temperature was raised to 205° C.at 1° C./min and held for 20 minutes. The temperature was raised to 315°C. at 1° C./min and held for approximately 60 minutes or until thedesired MV was reached as indicated by the torque rise on the stirrer.The required torque rise was determined from a calibration graph oftorque rise versus MV. The reaction mixture was then poured into a foiltray, allowed to cool, milled and washed with 2 litres of acetone andthen with warm water at a temperature of 40-50° C. until theconductivity of the waste water was <2 μS. The resulting polymer powderwas dried in an air oven for 12 hours at 120° C.

Examples 2 to 9—Preparation of Polyetheretherketone(PEEK)-Polyetherdiphenyletherketone (PEDEK) Copolymer

The procedure described in Example 1 was repeated except that thequantity of potassium carbonate and the mesh size used to sieve thesodium carbonate were varied to provide polyetheretherketone(PEEK)-polyetherdiphenyletherketone (PEDEK) copolymers of differentcrystallinity as shown in Table 1.

Example 10—Preparation of Polyetheretherketone(PEEK)-Polyetherdiphenyletherketone (PEDEK) Copolymer Based Upon Example1 of U.S. Pat. No. 4,717,761

A 0.5 litre flanged flask fitted with a ground glass lid,stirrer/stirrer guide, nitrogen inlet and outlet was charged with4,4′-diflurobenzophenone (112.38 g, 0.515 mol), 1,4-dihydroxybenzene(41.30 g, 0.375 mol), 4,4′-dihydroxydiphenyl (23.28 g, 0.125 mol) anddiphenylsulphone (243.10 g) and purged with nitrogen for 1 hour. Thecontents were then heated under a nitrogen blanket to 180° C. to form analmost colourless solution. While maintaining a nitrogen blanket, driedsodium carbonate (53.00 g, 0.5 mol) and potassium carbonate (0.35 g,0.003 mol), both sieved through a screen with a mesh of 500 micrometres,were added. The temperature was raised to 200° C. at 1° C./min and heldfor 60 minutes. The temperature was raised to 250° C. at 1° C./min andheld for 60 minutes. The temperature was raised to 300° C. at 1° C./minand held for 60 minutes. The reaction mixture was then poured into afoil tray, allowed to cool, milled and washed with 2 litres of acetoneand then with warm water at a temperature of 40-50° C. until theconductivity of the waste water was <2 μS. The resulting polymer powderwas dried in an air oven for 12 hours at 120° C.

Example 11—Preparation of Polyetheretherketone(PEEK)-Polyetherdiphenyletherketone (PEDEK) Copolymer

The procedure of Example 10 was followed except that the reagents ofExample 11 were reacted until a higher torque value was achievedcompared to Example 10, so the copolymer of Example 11 has a higher MV.

Example 12—Preparation of Polyetheretherketone(PEEK)-Polyetherdiphenyletherketone (PEDEK) Copolymer Based Upon U.S.Pat. No. 4,717,761

The procedure described in Example 10 was repeated except that theparticle size distribution of the sodium carbonate was increased (D50approximately 140 μm) to establish its effect on polyetheretherketone(PEEK)-polyetherdiphenyletherketone (PEDEK) copolymer crystallinity asshown in Table 1. The larger particle size of sodium carbonate resultedin no polymerisation taking place, so a further 4 mol % of sodiumcarbonate and 1 mol % of hydroquinone had to be added to the reaction.

Examples 13 & 14—Preparation of Polyetheretherketone(PEEK)-Polyetherdiphenyletherketone (PEDEK) Copolymer

A 0.5 litre flanged flask fitted with a ground glass lid,stirrer/stirrer guide, nitrogen inlet and outlet was charged with4,4′-diflurobenzophenone (111.29 g, 0.515 mol), 1,4-dihydroxybenzene(41.30 g, 0.375 mole), 4,4′-dihydroxydiphenyl (23.28 g, 0.125 mol) anddiphenylsulphone (24.09 g) and purged with nitrogen for 1 hour. Thecontents were then heated under a nitrogen blanket to 200° C. to form analmost colourless solution. While maintaining a nitrogen blanket, driedsodium carbonate (53.00 g, 0.5 mol) and potassium carbonate (3.46 g,0.025 mol), both sieved through a screen with a mesh of 500 micrometres,were added. The temperature was raised to 250° C. at 1° C./min and heldfor 15 minutes. The temperature was raised to 320° C. at 1° C./min andheld for 60 minutes. The reaction mixture was allowed to cool and standovernight under a nitrogen blanket. The following day the temperature ofthe mixture was raised to 320° C. and held for 150 minutes. The vesselwas then charged with 5 g of 4,4′-dichlorodiphenylsulfone and held at320° C. for a further 30 minutes. The reaction mixture was then pouredinto a foil tray, allowed to cool, milled and washed with 2 litres ofacetone and then with warm water at a temperature of 40-50° C. until theconductivity of the waste water was <2 μS. The resulting polymer powderwas dried in an air oven for 12 hours at 120° C.

Examples 15 to 24—Preparation of Polyetheretherketone(PEEK)-Polyetherdiphenyletherketone (PEDEK) Copolymer on a 200 Mol Scale

A 300 litre vessel fitted with a lid, stirrer/stirrer guide, nitrogeninlet and outlet was charged with diphenylsulphone (125.52 kg) andheated to 150° C. Once fully melted 4,4′-diflurobenzophenone (44.82 kg,205.4 mol), 1,4-dihydroxybenzene (16.518 kg, 150 mol) and4,4′-dihydroxydiphenyl (9.311 kg, 50 mol) were charged to the vessel.The contents were then heated to 160° C. While maintaining a nitrogenblanket, dried sodium carbonate (21.368 kg, 201.6 mol) and potassiumcarbonate (1.106 kg, 8 mol), both sieved through a screen with a mesh of500 micrometres, were added. The temperature was raised to 180° C. at 1°C./min and held for 100 minutes. The temperature was raised to 200° C.at 1° C./min and held for 20 minutes. The temperature was raised to 305°C. at 1° C./min and held until desired melt viscosity was reached, asdetermined by the torque rise of the stirrer. The required torque risewas determined from a calibration graph of torque rise versus MV. Thereaction mixture was poured via a band caster into a water bath, allowedto cool, milled and washed with acetone and water. The resulting polymerpowder was dried in a tumble dryer until the contents temperaturemeasured 112° C.

Examples 25 to 28—Preparation of Polyetheretherketone(PEEK)-Polyetherdiphenyletherketone (PEDEK) Copolymer on a 200 Mol Scale

The procedure described in Example 15 to 24 was repeated except that thequantity of DPS was 96.72 kg.

Table 1 below includes a summary of Examples 1 to 28. D50 as describedherein was determined as described in Example 29.

Example 29—General Procedure for Determining D50

The D₅₀ of sodium carbonate was determined by Malvern LaserDiffractometer, using the associated Mastersizer 3000 software. AFraunhofer type process was used to eliminate the requirement ofrefractive index figures for the samples. Using the Mastersizer 300software, the following instrument parameters were set:

Scattering Model Fraunhofer Background measurement duration 10.00 sSample measurement duration 10.00 s Number of measurements 2 Obscurationlow limit  1% Obscuration high limit 6% Obscuration time out  5.00 s AirPressure 1.5 barg Feed Rate 17% Venturi type Standard venturi disperserHopper gap 2.00 mm Analysis model General Purpose

A dried sample (<5 g) of carbonate was scooped into the hopper at thetop of the machine. A background measurement was run, and then twosample measurements were taken. The feed rate was started at 17%, butwas manually adjusted as the measurement was taken to ensure theobscuration measurement sat within the 1-6% limits.

In Table 1, the quantity of potassium carbonate is quoted in mole %.Unless otherwise stated herein, the mole % of potassium carbonate isdefined as:

$\frac{{the}\mspace{14mu}{number}\mspace{14mu}{of}\mspace{14mu}{moles}\mspace{14mu}{of}\mspace{14mu}{potassium}\mspace{14mu}{carbonate}}{{the}\mspace{14mu}{total}\mspace{20mu}{moles}\mspace{14mu}{of}\mspace{14mu}{hydroxy}\mspace{14mu}{{monomer}(s)}\mspace{14mu}{used}} \times 100\%$

Melt viscosity (MV) referred to in Table 1 may be determined asdescribed in Example 30.

Example 30—Determination of Melt Viscosity (MV) of Polymer

Unless otherwise stated, this was measured using capillary rheometryoperating at 340° C. at a shear rate of 1000 s⁻¹ using a tungstencarbide die, 0.5 mm×3.175 mm. The MV measurement was taken 5 minutesafter the polymer had fully melted, which is taken to be 5 minutes afterthe polymer is loaded into the barrel of the rheometer.

TABLE 1 Sodium Sodium Quantity Carbonate Carbonate Potassium ExampleSieve Size D₅₀ Carbonate MV (@ No. (μm) (μm) (mole %) 340° C.) 1 50096.7 4 0.22 2 125 67.7 0.25 0.22 3 125 67.7 2 0.28 4 300 93.1 0.25 0.145 300 93.1 2 0.34 6 500 96.7 0.25 0.12 7 500 96.7 0.25 0.13 8 500 96.70.25 0.31 9 500 96.7 2 0.34 10 500 96.7 0.5 0.18 11 500 96.7 0.5 0.30 12500 140 0.5 0.12 13 500 96.7 5 0.62 14 500 96.7 5 0.52 15 500 98.7 40.25 16 500 98.7 4 0.203 17 500 98.7 4 0.258 18 500 98.7 4 0.283 19 50098.7 4 0.324 20 500 98.7 4 0.222 21 500 98.7 4 0.26 22 500 98.7 4 0.26923 500 98.7 4 0.186 24 500 98.7 4 0.295 25 500 98.7 4 0.406 26 500 98.74 1.707 27 500 98.7 4 1.305 28 500 98.7 4 0.853

Example 31—Differential Scanning Calorimetry of Polyaryletherketones ofExamples 1 to 28

Crystallinity (as reported in Table 2) may be assessed by severalmethods for example by density, by ir spectroscopy, by x ray diffractionor by differential scanning calorimetry (DSC). The DSC method has beenused to evaluate the crystallinity that developed in the polymers fromExamples 1-28 using a Mettler Toledo DSC1 Star system with FRS5 sensor.

The Glass Transition Temperature (Tg), the Cold CrystallisationTemperature (Tn), the Melting Temperature (Tm) and Heat of Fusions ofNucleation (ΔHn) and Melting (ΔHm) for the polymers from Examples 1 to28 were determined using the following DSC method.

A dried sample of each polymer was compression moulded into an amorphousfilm, by heating 7 g of polymer in a mould at 400° C. under a pressureof 50 bar for 2 minutes, then quenching in cold water producing a filmof dimensions 120×120 mm, with a thickness in the region of 0.20 mm. An8 mg plus or minus 3 mg sample of each film was scanned by DSC asfollows:

-   Step 1 Perform and record a preliminary thermal cycle by heating the    sample from 30° C. to 400° C. at 20° C./min.-   Step 2 Hold for 5 minutes.-   Step 3 Cool at 20° C./min to 30° C. and hold for 5 mins.-   Step 4 Re-heat from 30° C. to 400° C. at 20° C./min, recording the    Tg, Tn, Tm, ΔHn and ΔHm.

From the DSC trace resulting from the scan in step 4, the onset of theTg was obtained as the intersection of the lines drawn along thepre-transition baseline and a line drawn along the greatest slopeobtained during the transition. The Tn was the temperature at which themain peak of the cold crystallisation exotherm reaches a maximum. The Tmwas the temperature at which the main peak of the melting endothermreach maximum.

The Heat of Fusion for melting (ΔHm) was obtained by connecting the twopoints at which the melting endotherm deviates from the relativelystraight baseline. The integrated area under the endotherm as a functionof time yields the enthalpy (mJ) of the melting transition: the massnormalised heat of fusion is calculated by dividing the enthalpy by themass of the specimen (J/g). The level of crystallisation (%) isdetermined by dividing the Heat of Fusion of the specimen by the Heat ofFusion of a totally crystalline polymer, which for polyetheretherketoneis 130 J/g.

Results are provided in Table 2.

Polymer Level of from Tg Tn ΔH_(n) Tm ΔH_(m) Crystallinity Example (°C.) (° C.) (J/g) (° C.) (J/g) (%) 1 148.00 n/a n/a 305.00 35.47 28.55 2147.21 204.80 7.30 304.18 33.10 19.54 3 150.27 n/a n/a 303.05 30.4223.40 4 148.18 n/a n/a 306.47 32.40 24.93 5 149.06 n/a n/a 303.51 32.2524.81 6 140.47 n/a n/a 305.41 34.87 26.82 7 148.78 n/a n/a 306.73 25.7527.50 8 147.00 200.10 2.75 302.11 33.17 23.68 9 148.26 n/a n/a 303.1930.56 23.51 10 150.09 n/a n/a 305.52 32.72 25.63 11 149.19 n/a n/a303.47 31.79 24.45 12 148.47 n/a n/a 307.68 37.17 28.59 13 153.65 n/an/a 303.67 26.04 20.04 14 152.76 n/a n/a 302.14 27.38 21.06 15 150.42n/a n/a 304.57 38.77 29.83 16 149.6 n/a n/a 305.58 39.88 30.68 17 150.03n/a n/a 306.45 36.99 28.45 18 150.86 n/a n/a 306.32 37.19 28.6 19 150.84n/a n/a 306.41 36.56 28.12 20 150.2 n/a n/a 307.68 36.82 28.32 21 150.34n/a n/a 306.67 39.84 30.65 22 150.21 n/a n/a 307.03 35.47 27.28 23150.03 n/a n/a 306.72 39.64 30.49 24 150.11 n/a n/a 292.36 43.03 33.1125 149.1 n/a n/a 301.6 n/a 27.00 26 154.0 n/a n/a 294.0 n/a 17.50 27152.5 n/a n/a 296.5 n/a 20.40 28 151.7 n/a n/a 297.6 n/a 21.60

Example 32—Mechanical Properties

The mechanical properties of a blend of the materials of Examples 15 to19 to give an MV of 0.25 kNsm⁻² were assessed in a series of tests andthe results are provided in Table 3.

Table 3 also quotes results of mechanical tests undertaken oncommercially available Victrex PEEK 150 for comparison.

TABLE 3 Test Conditions Method Units Value PEEK150 Tensile Yield, ISO527 MPa 94 110 strength 23° C. Tensile Break, ISO 527 % 24 25 Elongation23° C. Tensile 23° C. ISO 527 GPa 3.5 3.7 Modulus Flexural 23° C. ISO178 MPa 145 130 Strength Flexural 23° C. ISO 178 GPa 3.5 4.3 ModulusIzod impact Notched, ISO 180/U kJ m⁻² 5.2 5.0 Strength 23° C.

Discussion

In general terms, it is found that the process described herein can beused to produce PEEK:PEDEK copolymers which have advantageously highercrystallinities than expected. Referring to FIG. 1, the results fromTables 1 and 2 are plotted. The graph describes log₁₀ (X %) (i.e. log₁₀of the % crystallinity measured by DSC as described) v. the meltviscosity (MV) determined as described (i.e. using capillary rheometryoperating at 340° C. at a shear rate of 1000 s-¹ using a tungstencarbide die 0.5 mm×3.175 mm. FIG. 1 shows a first series of points,being the results for Examples 1 and 15 to 28, (represented by squares)which have a crystallinity for a selected MV which is higher than asecond series of points, being the results for Examples 2 to 14,(represented by triangles). The first series of points relate topolymeric materials made in processes which use at least 2.5 mole %based on the total moles of hydroxy monomer(s), whereas the secondseries of points use less than 2.5 mole % potassium carbonate based onthe total moles of hydroxy monomer(s) (Examples 2 to 12) or use 5 mole %potassium carbonate based on the total moles of hydroxy monomer(s)(Examples 13 and 14). It is clear that the level of potassium carbonateused affects the crystallinity of the PEEK:PEDEK copolymer, resulting incrystallinity which is higher than would be expected for example basedon the disclosure in U.S. Pat. No. 4,717,761. The equation of the linefor the second series of points is found to belog₁₀(X %)=1.45−0.24 MV

FIG. 1 also includes a first calculated dividing line above the secondseries of points. The calculated dividing line is included to delineatepolymeric materials which are in accordance with preferred embodimentsof the invention (i.e. materials found above the dividing line) fromthose which are not in accordance with preferred embodiments of theinvention (i.e. materials found below the dividing line). The equationof the dividing line is:log₁₀(X %)=1.50−0.26 MV

Thus, for polymeric materials in accordance with preferred embodiments,the following relationship applies:log₁₀(X %)>1.50−0.26 MV

FIG. 1 includes a second calculated dividing line above the firstcalculated dividing line, the second dividing line defines morepreferred embodiments. Thus, more preferred embodiments fall above thesecond calculated dividing line and the following relationship applies:log₁₀(X %)>1.50−0.23 MVwhere X and MV are determined as described.

FIG. 3 includes a third calculated dividing line above the secondcalculated dividing line. The third line defines especially preferredembodiments. Thus, especially preferred embodiments fall above the thirdcalculated dividing line and the following relationship applies:log₁₀(X %)>1.50−0.28 MV+0.06 MV²where X and MV are determined as described.

On the basis of the Examples described and other examples, therelationship graphically represented in FIG. 2 was determined. Thereference to “poor crystallinity” means the crystallinity of thePEEK:PEDEK copolymers was less than 25%; and the reference to “goodcrystallinity” means the crystallinity of the copolymer was greater than25%.

Referring to FIG. 2, preferred embodiments of the present invention usea process wherein the mole % of potassium carbonate based on the totalmoles of hydroxy monomer(s) is greater than 2.5 mole % or the followingapplies:

$\frac{D\; 50\mspace{14mu}{of}\mspace{14mu}{sodium}\mspace{14mu}{carbonate}\mspace{14mu}{in}\mspace{14mu}{µm}}{{mole}\mspace{14mu}\%\mspace{14mu}{of}\mspace{14mu}{potassium}\mspace{14mu}{carbonate}}$is less or equal to 46.

In view of the differences between polymeric materials in accordancewith preferred embodiments of the present invention and other materialsdescribed, NMR was used to assess materials as described in Example 28.

Example 33—NMR Analysis of PEEK:PEDEK Polymers and Comparison with PEEKPolymer

Pressed films made from the polymeric materials of Example 21 (amaterial in accordance with a preferred embodiment of the invention),Example 4, Example 10 and PEEK 150 were assessed to determine anystructural differences.

For the analysis a portion of each pressed film was dissolved in methanesulphonic acid/methylene dichloride solvent (the standard solvent usedfor polyaryletherketone polymers). In each case, the resulting solutionswere clear to the naked eye, suggesting total solubility.

The solutions were examined using a Lambda 300 instrument at 25° C. toproduce ¹³C NMR spectra. The carbonyl region of the spectrum wasexpanded and three carbonyl groups were identified in slightly differentchemical environments as follows:

199.7 ppm PEEK homopolymer (seen in the PEEK 150 material assessed);

199.35 ppm PEDEK homopolymer;

199.5 ppm PEEK:PEDEK interchange unit (nb this resonance would not bepresent if the sample was a blend of two homopolymers (i.e. PEEK andPEDEK)).

On the basis that the PEEK:PEDEK copolymers have a 75:25 composition,the theoretical areas that would result from the aforementionedresonances if a sample was 100% random was determined. Then, the areasmeasured in the spectra were compared to the theoretical value yieldinga % randomness of each PEEK:PEDEK material as described below.

Example No. % randomness 10 30 4 23 21 38

Thus, it appears the process used in accordance with preferredembodiments of the invention results in production of a more randomcopolymer which results in an increase in crystallinity over and abovethe level of crystallinity that may be expected.

The invention is not restricted to the details of the foregoingembodiment(s). The invention extends to any novel one, or any novelcombination, of the features disclosed in this specification (includingany accompanying claims, abstract and drawings), or to any novel one, orany novel combination, of the steps of any method or process sodisclosed.

The invention claimed is:
 1. A polymeric material having a repeat unitof formula—O-Ph-O-Ph-CO-Ph-  I and a repeat unit of formula—O-Ph-Ph-O-Ph-CO-Ph-  II wherein Ph represents a phenylene moiety;wherein the repeat units I and II are in the relative molar proportionsI:II of from 65:35 to 95:5; wherein the melt viscosity MV of thepolymeric material is at least 0.2 kNsm⁻² and less than 1.8 kNsm⁻² asmeasured by capillary rheometry at 340° C. at a shear rate of 1000 s⁻¹using a tungsten carbide die 0.5 mm×3.175 mm; wherein log₁₀ (X%)>1.50-0.26 MV; wherein X % refers to the % crystallinity of an 8+/−3mg sample from a cold-water quenched 120 mm×120 mm×0.2 mm amorphous filmof the polymeric material formed by compression moulding 7 g of thepolymeric material at 400° C. under a pressure of 50 bar for 2 minutes;wherein the % crystallinity is measured by heating the 8+/−3 mg samplein a differential scanning calorimeter from 30° C. to 400° C. at 20°C./min, held at 500° C. for 5 minutes, cooled to 30° C. at 20° C./minthen held at 30° C. for 5 minutes prior to re-heating from 30° C. to400° C. at 20° C./min to provide a melting endotherm as a function oftime; wherein the heat of fusion for melting in J/g is obtained byconnecting two points at which the melting endotherm differs from thestraight baseline, integrating the area under the melting endotherm, anddividing the area by the sample weight; wherein the % crystallinity isobtained by expressing the heat of fusion as a percentage of 130 J/g;and wherein the melting temperature Tm of the polymeric material is lessthan 320° C.; wherein said polymeric material is prepared by processcomprising polycondensing a mixture of at least one dihydroxybenzenecompound and at least one dihydroxybiphenyl compound in the molarproportions 65:35 to 95:5 with at least one dihalobenzophenone in thepresence of sodium carbonate and potassium carbonate wherein: (i) themole % of said potassium carbonate is in a range 2.5 to 4.9% and isdefined as$\frac{{the}\mspace{14mu}{number}\mspace{14mu}{of}\mspace{14mu}{moles}\mspace{14mu}{of}\mspace{14mu}{potassium}\mspace{14mu}{carbonate}}{{the}\mspace{14mu}{total}\mspace{14mu}{number}\mspace{14mu}{of}\mspace{14mu}{moles}\mspace{14mu}{of}\mspace{14mu}{hydroxy}\mspace{14mu}{{monomer}(s)}\mspace{14mu}{used}} \times 100.$2. A polymetric material according to claim 1, wherein at least 95% ofthe number of phenylene moieties (Ph) in the repeat unit of formula Ihave 1,4-linkages to moieties to which they are bonded; and at least 95%of the number of phenylene moieties (Ph) in the repeat unit of formulaII have 1,4-linkages to moieties to which they are bonded.
 3. Apolymetric material according to claim 1, wherein log₁₀ (X %)>1.50−0.23MV.
 4. A polymeric material according to claim 1, wherein log₁₀ (X%)>1.50−0.28 MV+0.06 MV2.
 5. A polymetric material according to claim 1,which includes 68 mol % to 82 mole % of units of formula I.
 6. Apolymetric material according to claim 1, which includes 72 to 77 mole %of units of formula I.
 7. A polymetric material according to claim 1,which includes 18 to 32 mole % of units of formula II.
 8. A polymetricmaterial according to claim 1, which includes 23 to 28 mole % of unitsof formula II.
 9. A polymetric material according to claim 1, whereinT_(m) is in the range 300° C. to 310° C.
 10. A polymetric materialaccording to claim 1, wherein said polymeric material has a T_(g) in therange 145° C.-155° C., a T_(m) in the range 300° C. to 310° C. and thedifference between the T_(m) and T_(g) is in the range 145° C. to 165°C.
 11. A polymetric material according to claim 1, which has acrystallinity of at least 25%.
 12. A material according to claim 1,wherein the mole % of said potassium carbonate is in the range 3.5 to4.9%.
 13. A polymetric composition comprising a material according toclaim 1 and a filler.
 14. A composition according to claim 13, whereinsaid filler comprises one or more fillers selected from glass fibre,carbon fibre, carbon black, talc, and a fluorocarbon resin.
 15. Aprocess for the production of a polymeric material having a repeat unitof formula—O-Ph-O-Ph-CO-Ph-  I and a repeat unit of formula—O-Ph-Ph-O-Ph-CO-Ph-  II wherein Ph represents a phenylene moiety, saidprocess comprising polycondensing a mixture of at least onedihydroxybenzene compound and at least one dihydroxybiphenyl compound inthe molar proportions 65:35 to 95:5 with at least one dihalobenzophenonein the presence of sodium carbonate and potassium carbonate wherein: (i)the mole % of said potassium carbonate is in a range 2.5 to 4.9% and isdefined as$\frac{{the}\mspace{14mu}{number}\mspace{14mu}{of}\mspace{14mu}{moles}\mspace{14mu}{of}\mspace{14mu}{potassium}\mspace{14mu}{carbonate}}{{the}\mspace{14mu}{total}\mspace{14mu}{number}\mspace{14mu}{of}\mspace{14mu}{moles}\mspace{14mu}{of}\mspace{14mu}{hydroxy}\mspace{14mu}{{monomer}(s)}\mspace{14mu}{used}} \times 100.$16. A process according to claim 15, wherein the mole % of sodiumcarbonate used in the process is at least 90 mole %.
 17. A processaccording to claim 15, wherein the D₅₀/mole % relationship is less than30.
 18. A process according to claim 15, which comprises selecting adihydroxybenzene compound of formula

and selecting a dihydroxybiphenyl compound of formula

wherein molar proportions of compounds V and VI are in the range 65:35to 95:5, the process comprising polycondensing said compounds offormulas V and VI with a compound of formula

where X¹ and X² independently represent halogen atoms.
 19. A processaccording to claim 18, wherein at least 95 wt % of monomers used in theprocess are made up of monomers of formulae V, VI and VII.
 20. A processaccording to claim 15, wherein the following relationship (referred toas the “D₅₀/mole % relationship”) applies$\frac{{the}\mspace{14mu} D_{50}\mspace{14mu}{of}\mspace{14mu}{said}\mspace{14mu}{sodium}\mspace{14mu}{carbonate}\mspace{14mu}{in}\mspace{14mu}{µm}}{{mole}\mspace{14mu}\%\mspace{14mu}{of}\mspace{14mu}{potassium}\mspace{14mu}{carbonate}} = {< 46.}$21. A process according to claim 15, wherein the process furthercomprises a step of sieving the sodium carbonate and potassium carbonatethrough a screen with a mesh of 500 micrometers.
 22. A process accordingto claim 15, wherein the mole % of said potassium carbonate is in therange 3.5 to 4.9%.